Enabling X11 Forwarding on Mac OS X

By default, X11 forwarding is not enabled on Mac Leopard. To enable it you need to have a line like "X11Forwarding yes" in the file /private/etc/sshd_config. Just do this command from the terminal.

$ sudo echo "X11Forwarding yes" >> /private/etc/sshd_config
Enter the password when prompted.

Make sure that you check Remote Login under Sharing in System Preferences.

$ ssh -X username@remotehost
$ xeyes &
$ xclock &

For the xeyes you should see the eyes on your screen. For the xclock it's clock. On our clusters we are not allowed to be idle for more than certain time and so I use xclock to keep it active all the time.